Conventional depth images provide the viewer with a sense of depth which is some times called binocular stereopsis. Conventional depth image displays, either of the lenticular or barrier type, because a stereo effect is being provided, present slightly different scene information to the viewer as the viewer's head moves in a horizontal direction in front of the depth image. This effect called a look around effect occurs because each eye is presented with a different image or view of the scene. As the position of the eye moves relative to the depth image the view presented to each eye changes. Because the mind of the viewer fuses the slices of the same scene reaching each eye the viewer senses depth in the photograph being viewed. If the different view points of the scene gradually expose a hidden object, the viewer experiences the ability to look around objects in the depth photograph. This experience of depth is provided even though the lenticular photograph is a generally planar object.
The ability of the lenticular photograph to provide different image slices to the eye is possible because an image substrate includes adjacently recorded image slices each of which is projected in a different direction by the cylindrically shaped lenses, called lenticules, which are part of the lenticular face plate positioned in front of the substrate. In barrier type depth images a barrier strip face plate is substituted for the lenticular face plate. Additional information on the background and the theory of depth images can be obtained from Okoshi, Three-Dimensional Imaging Techniques, 1976 published by Academic Press. Conventional depth images, such as those discussed above, present the viewer with images from the same scene with changes in image information being limited to changes in content being provided by different viewpoints of the same scene. Lenticular viewing devices currently exist in which the information presented changes as the viewpoint of the lenticular object changes. These objects, typified by lenticular baseball cards and prizes found in boxes of caramel coated nuts and popcorn, present the viewer with different pictures of different scenes as the vertical viewpoint changes. For example, from one viewpoint the viewer would see a picture of a baseball player and from a different vertical viewpoint the viewer would see a picture of a different baseball player. These pictures are planar pictures with no sense of depth being provided.
However, technology has developed to provide a depth image that radically changes the information provided to the viewer as the viewpoint changes horizontally while the sense of realistic motion or depth is preserved. It is contemplated the depth image may incorporate information not related to the depth image scene can be provided to the viewer from different viewpoint orientations. The resulting depth image creates an image sequence of gradually changing display information, either temporal or spatial, unrelated to the depth content in conjunction with sufficient information being presented in each successive horizontal image to enable binocular stereoptic motion, movement or depth perception in a viewer when positioned at one or more possible horizontal viewing locations in the viewing space. The depth image may present such changing information as photographically captured images or computer generated graphics or text which is superimposed on view perspective changing information to be concurrently visible at one or more possible locations in the viewing space. In fact, the depth images may include dissimilar information compiled from two or more distinct sources of image sequences with sufficient information being retained to provide the viewer with a sense of depth, motion or binocular stereopsis at one or more locations in the viewing space. Therefore, a depth image may provide the viewer with animation of a scene as the viewer changes horizontal head position while maintaining a sense of depth, motion or binocular stereopsis. Further, multiple depth images from the same image space may be provided. That is, a depth image in which information in addition to the conventional depth information changes as the viewer's head changes position is now possible. Further, these depth images may be back lit or front lit. A back lit depth image will allow an illuminating light to pass from the rear of the depth image, through the media of the depth image and out the front, or viewed side of the depth image. Conversely, the media of a front lit depth image is opaque and the illuminating light must reflect of the front surface of the depth image. U.S. Pat. No. 5,543,964 to Taylor et. al, assigned to Eastman Kodak Company, based on U.S. Ser. No. 08/174,657 filed Dec. 28, 1993 is herein incorporated by reference.
It is contemplated these depth images may be used in promotional materials, advertising point of purchase displays, as well as scientific and medical information transfers. That is, in some applications there may be a real time viewing parameter that allows the changing display information to reproduce a temporal parameter accurately. Specifically, if the depth image includes human motion or certain physiology, or chemical reactions, an important aspect of the information captured in the depth image may reside in the temporal relations.
Conventional electronically printed lenticular photographs are printed hard copy images that change in appearance with viewer orientation to the display. In these conventional applications of the technology, the changing viewing perspective of a single static image scene enables stereopsis by the viewer with a look around effect which creates an experience analogous to viewing the real world. The present depth images, in contrast to this conventional technology, radically changes the information or content of the image seen by the viewer at different angular locations, display bands or display spaces within the display angle of a lenticular face plate of a lenticular photograph while maintaining the viewer's perception of depth, motion or the stereopsis effect.
Therefore, a need exists for a device and method to reproducibly view a depth image. Preferably, the device and method are economical to produce, while providing repeated uses without failure. In a preferred embodiment, the device can accommodate a variety of viewing or replay speeds. In addition, the need exists for a device to allow successive viewing of a plurality of depth images. A further need exists for the display of back lit or front lit depth images.